Thunder over Louisville is set for April 20 and organizers announced this year's theme.

There are only 67 days left until the official launch of the Kentucky Derby Festival. There's still a lot of planning left to do, but so far, the planners say they're very excited over the upcoming attractions and this year's new theme.

Sponsors unveiled this year's Thunder Over Louisville poster.

The poster is in 3D and requires special glasses to view it.

The idea is to reflect this year's new theme, Thunder Vision, as a tribute to classic and modern TV shows.

“We've gone back over 50-plus years of television programming with our soundtrack, and trying to mesh together a soundtrack for the fireworks. Now we are going to have some of the patriotic tunes and stuff mixed-in with it,” said Thunder Over Louisville producer Wayne Hettinger.

Organizers say Thunder is still the largest single-day event in the Southeast, bringing $56 million annually to the local economy.

The show is months away, but organizers say there's still much planning left to do.

“The new stuff, we're still working on. We've got some trial and error stuff going on with fireworks, we've got some commitments from aircraft waiting. It's still too early to say for sure, here's what's happening,” said Hettinger.

Organizers say the amount of military planes in the air show may be affected by recent military cutbacks.

"Air Boss" Mike Riordan says there will still be plenty of civilian planes to entertain.

“You'll actually see something this year that's never been seen before in Thunder. We'll have more aircraft in the box at one time than you've ever seen before,” said Riordan.

Just like last year, some areas will still require the $5 Pegasus Pin. Those will include the beer garden, the North Great Lawn, and the chow wagon.

An estimated 700,000 people will attend Thunder Over Louisville.

The newly opened Big Four Bridge will be closed during this year's event.